A magnetorheological damper capable of force and displacement sensing

A magnetorheological (MR) damper with embedded force and displacement sensors is devised to facilitate closed-loop structural vibration control. A piezoelectric force sensor and a linear variable differential transformer (LVDT) have been integrated with a conventional MR damping device. The piezoelectric sensor is used to sense the damping force produced by the damper, while the LVDT is employed to measure the displacement of the vibrating structure at the damper location and the movement of the damper piston. Calibration of the piezoelectric force sensor is conducted through force-controlled tests with sinusoidal force excitations of different amplitudes and frequencies. The sensing and damping performances of the devised MR damper are evaluated under displacement-controlled excitations, with different current inputs being commanded to the damper. The experimental results demonstrate reliable displacement/force sensing and controllable damping capabilities of the devised damper. The sensing-while-damping function of the damper hence offers its potential for real-time feedback structural vibration control.